1. Field of the Invention
This invention relates to a paper magazine for feeding and rewinding a photographic paper from and onto a roll of paper rotatably mounted on the magazine and used e.g. to feed a web of photographic paper to a photographic printing apparatus.
2. State of the Prior Art
As shown in FIG. 20, a photographic printing apparatus has a light source 81 that emits light through a mirror tunnel 82 at a negative film 84 on a negative mask 83 to print negative images on the negative film 84 through a printing lens 85 onto photographic paper P on an exposure unit 86.
This conventional photographic printing apparatus B carries a plurality of paper magazines A, A' accommodating a roll R of photographic paper P having different print sizes from each other. The photographic paper P in one of the paper magazines A is pulled out to the exposure unit 86 for printing. When changing the print size, after rewinding the photographic paper into the paper magazine A, the photographic paper in the other paper magazine A' is pulled out.
When changing the photographic paper in one paper magazine to the paper in the other, a cutter device 87 disposed in the feed path of photographic paper extending from the paper magazine A to the exposure unit 86 is activated to cut the photographic paper P. Then, the portion of the photographic paper P that protrudes from the paper magazine A is rewound into it. Then, the photographic paper P in the other paper magazine A' is pulled out until its tip is caught between a pair of advance rollers 54 provided in the paper feed path.
Such conventional paper magazines for feeding and rewinding photographic paper come in two types, that is, the type having a built-in feeding and rewinding mechanism and the type having no such mechanism. When using a paper magazine of the latter type, photographic paper is put in the magazine with its tip protruding slightly from the magazine. The magazine is then set in the photographic printing apparatus with the protruding end of the paper caught between the advance rollers 54.
On the other hand, a paper magazine of the former type has a feed roller adapted to be pressed against the photographic paper provided near the paper outlet of the paper magazine. By manually controlling a knob coupled to the feed roller, the photographic paper is fed and rewound.
When using a paper magazine without the feeding and rewinding mechanism, since the tip of the paper has to protrude from the magazine, this portion is necessarily exposed to light. Useless portions thus form on the paper.
Also, it is necessary to pull out the photographic paper so that its leading end can be caught between the advance rollers. If pulled out too much, the unnecessary portion has to be cut off. Such work is extremely troublesome.
On the other hand, a paper magazine having the feeding/rewinding mechanism has a problem in that since the feed rollers are always pressed against the photographic paper, it is likely to develop indentations and surface irregularities. Also, when feeding, the paper is likely to meander.
Also, since the length by which the photographic paper can be fed or rewound is limited, it is difficult to use a single magazine for different kinds of photographic printing apparatus.
Besides, in either of the abovementioned paper magazines, the paper is rewound onto the core of the paper roll in the magazine by rotating the core itself. Thus, if the paper rear end should come off the core of the paper roll, it becomes impossible to further rewind the paper. This means that the entire part of the paper in the feed path in the magazine is wasted.